Wikileaks, a fine website with a history of exposing documents the powerful would rather keep hidden, has released this:
This significant, previously unpublished document (classified “RESTRICTED”, 2389 pages), is the UK military protocol for security operations, including counter-intelligence.
The document includes instructions on dealing with leaks, investigative journalists, Parliamentarians, foreign agents, terrorists & criminals, sexual entrapments in Russia and China, diplomatic pouches, allies, classified documents & codewords, compromising radio and audio emissions, computer hackers—and many other related issues.